Hamstring Strain (Posterior Thigh Muscle Strain)

Also known as: Hamstring muscle strain, Hamstring strain, Posterior thigh strain, Hamstring pull, Pulled hamstring, Hamstring tear, Hamstring muscle tear

Last updated: December 18, 2024

A hamstring strain is an injury to one or more muscles along the back of the thigh, caused by overstretching or tearing that can range from tiny fiber damage to complete rupture. It often happens during sprinting, jumping, kicking, or sudden directional changes. Symptoms include sudden sharp posterior thigh pain and tenderness. Severity is often graded I–III. Mild cases may improve in days to a few weeks; moderate strains may last several weeks.

Key Facts

•A hamstring strain involve overstretching or tearing of one or more hamstring muscles along the back of the thigh, ranging from microscopic fiber disruption to a complete rupture
•Sudden posterior thigh pain that occurs during sprinting, kicking, or jumping and be described as sharp or stabbing
•Diagnosed through history, physical exam, and imaging
•First-line treatment includes exercise, weight management, and activity modification

What It Is

A hamstring strain may involve overstretching or tearing of one or more hamstring muscles along the back of the thigh, ranging from microscopic fiber disruption to a complete rupture. The injury can occur within the muscle belly, at the musculotendinous junction, or near the tendon attachment to bone, and it often results from rapid eccentric loading during sprinting, jumping, or sudden directional changes. Local bleeding and inflammation can contribute to pain, swelling, and reduced strength, and more extensive injury can involve tendon retraction or associated bruising. Severity is often described clinically as mild (grade I), partial tear (grade II), or complete tear (grade III), although imaging may refine characterization.

Affected Anatomy

This condition affects several structures in and around the joint:

•Biceps femoris (long head) muscle and tendon
•Biceps femoris (short head) muscle
•Semitendinosus muscle and proximal tendon
•Semimembranosus muscle and proximal tendon
•Musculotendinous junction of the hamstring complex
•Ischial tuberosity (proximal hamstring origin on the pelvis)
•Sciatic nerve (adjacent structure that can be irritated by swelling or hematoma)
•Posterior thigh fascia and intramuscular connective tissue septa

Common Symptoms

Symptoms can vary in intensity and may change over time. Common experiences include:

•Sudden posterior thigh pain that may occur during sprinting, kicking, or jumping and can be described as sharp or stabbing
•Pain that may worsen with activity and can also be present at rest, particularly with more extensive fiber disruption
•Tenderness along the hamstring muscle belly or near the sit-bone region, often with focal point tenderness at the musculotendinous junction
•Swelling or a feeling of tightness in the back of the thigh that can develop over hours after injury
•Bruising (ecchymosis) that may appear hours to days later and can track down the thigh due to gravity
•Weakness with knee flexion and/or hip extension that can limit walking speed, stair climbing, or running
•Reduced flexibility or painful stretching sensation during hip flexion with the knee extended
•A popping sensation at the time of injury or a palpable defect that may suggest a higher-grade tear

Causes and Risk Factors

Multiple factors can contribute to the development of this condition:

Causes

•Eccentric overload during high-speed running, where the hamstrings can lengthen while contracting to decelerate the swinging leg
•Sudden acceleration, deceleration, or cutting movements that can increase tensile stress at the musculotendinous junction
•Forceful hip flexion with knee extension (for example, high kicks or slips) that can strain proximal hamstring fibers near the ischial origin
•Direct trauma to the posterior thigh that can contribute to muscle fiber disruption and hematoma formation
•Inadequate neuromuscular control or fatigue-related coordination changes that can increase strain on hamstring fibers late in activity
•Reinjury in previously damaged tissue where scar formation can alter load distribution and tissue compliance

Risk Factors

•Prior hamstring strain, which can be associated with altered biomechanics and residual strength or flexibility deficits
•Participation in sports involving sprinting, kicking, or rapid direction changes (for example, soccer, football, track sprinting)
•Muscle fatigue, which can reduce eccentric strength and timing of hamstring activation
•Imbalance between quadriceps and hamstring strength, particularly reduced eccentric hamstring strength relative to quadriceps output
•Limited hip flexor flexibility or reduced hamstring flexibility that can increase strain during terminal swing phase of running
•Poor lumbopelvic control or altered pelvic tilt mechanics that can change hamstring length-tension relationships
•Older age in athletic populations, which can be associated with reduced tissue elasticity and slower recovery capacity
•Inadequate warm-up or rapid increase in training load, which can increase susceptibility to soft-tissue injury

How It's Diagnosed

Diagnosis typically involves a combination of clinical assessment and imaging studies:

•Clinical history focusing on mechanism (sprinting, kicking, overstretch), timing of pain onset, audible pop, and functional limitations
•Physical examination including inspection for swelling or bruising, palpation to localize tenderness, and assessment for a palpable defect
•Range-of-motion testing of hip and knee, often including passive straight-leg raise or active knee extension measures to characterize flexibility limitation and pain provocation
•Strength testing of knee flexion and hip extension, which can include comparison to the uninjured side and assessment across different knee angles
•Functional assessment such as gait evaluation and sport-specific movement screening, which can help characterize severity and readiness for progressive activity
•Ultrasound imaging, which can help identify fiber disruption, hematoma, and some tendon injuries, often with dynamic assessment
•MRI, which can help grade injury extent, localize involvement (muscle belly versus tendon), evaluate proximal hamstring origin injury, and assess for tendon retraction or large hematoma

Treatment Options

Treatment approaches range from conservative measures to surgical interventions, often starting with the least invasive options:

Self-Care and Activity Modification

•Relative rest and activity modification, which can allow symptoms to settle while avoiding movements that provoke sharp pain
•Cold therapy applied intermittently early after injury, which may reduce pain and limit swelling in some individuals
•Compression and elevation strategies, which can help manage swelling and bruising in the acute phase
•Neuromuscular and lumbopelvic stabilization training, which can address movement control factors associated with recurrence risk
•Gradual return-to-sport progression using functional criteria (pain-limited strength, flexibility, and sport-specific drills) rather than time alone

Physical Therapy and Exercise

•Physical therapy emphasizing progressive range-of-motion work, gradual strengthening, and eccentric hamstring loading as tolerated
•Adjunct modalities sometimes used in rehabilitation (for example, manual therapy, soft-tissue techniques, or therapeutic ultrasound), with variable evidence across protocols

Medications

•Analgesic options such as acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs), which can be used in some cases for symptom control depending on individual factors and clinician guidance

Surgery

•Management of large hematoma or suspected complete rupture with specialist evaluation, which can include consideration of procedural or surgical options in selected cases
•Surgical repair, which may be considered for complete proximal hamstring tendon avulsions, significant tendon retraction, or persistent functional limitation despite structured rehabilitation

Prognosis and Recovery

The course of this condition varies between individuals:

•Mild strains can often improve over days to a few weeks, while moderate strains can span several weeks, depending on tissue involvement and functional demands
•More extensive tears, particularly those involving proximal tendon injury or significant retraction, can require longer recovery spans and may involve higher risk of persistent weakness
•Reinjury can occur, especially during early return to high-speed running, and recurrence risk may relate to residual eccentric strength deficits or incomplete functional restoration
•Imaging findings can correlate imperfectly with symptoms, and functional testing can often provide additional context for recovery status
•Long-term outcomes can be favorable with structured rehabilitation, although some individuals can experience lingering tightness, discomfort with sprinting, or reduced performance for a period

Physical Therapy (Physiotherapy)(Procedure)
Platelet-Rich Plasma (PRP) Therapy(Procedure)

Frequently Asked Questions

Common symptoms include: Sudden posterior thigh pain that may occur during sprinting, kicking, or jumping and can be described as sharp or stabbing; Pain that may worsen with activity and can also be present at rest, particularly with more extensive fiber disruption; Tenderness along the hamstring muscle belly or near the sit-bone region, often with focal point tenderness at the musculotendinous junction; Swelling or a feeling of tightness in the back of the thigh that can develop over hours after injury; Bruising (ecchymosis) that may appear hours to days later and can track down the thigh due to gravity.

Diagnosis typically involves: Clinical history focusing on mechanism (sprinting, kicking, overstretch), timing of pain onset, audible pop, and functional limitations; Physical examination including inspection for swelling or bruising, palpation to localize tenderness, and assessment for a palpable defect; Range-of-motion testing of hip and knee, often including passive straight-leg raise or active knee extension measures to characterize flexibility limitation and pain provocation; Strength testing of knee flexion and hip extension, which can include comparison to the uninjured side and assessment across different knee angles.

Treatment options range from conservative measures to surgical interventions, including: Relative rest and activity modification, which can allow symptoms to settle while avoiding movements that provoke sharp pain; Cold therapy applied intermittently early after injury, which may reduce pain and limit swelling in some individuals; Compression and elevation strategies, which can help manage swelling and bruising in the acute phase; Analgesic options such as acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs), which can be used in some cases for symptom control depending on individual factors and clinician guidance; Physical therapy emphasizing progressive range-of-motion work, gradual strengthening, and eccentric hamstring loading as tolerated.